why is my galaxy mega 6.3 doesn't totally turning on?

two days ago my galaxy mega 6.3 hang up so i removed its battery to shut it down and reboot it. it does turned on but when samsung logo shows it got stock there. i kept rebooting my galaxy mega for two days now but everytime it turned on it always get stocked on the samsung logo and doesn't the device does not open totally

Welcome to Android Central! Try booting into Recovery Mode and wiping the cache partition, which won't erase any personal data. Follow the steps in this video, but instead of selecting Wipe Data/Factory Reset, make sure you select Wipe Cache Partition. When complete, then select Reboot System Now.